Apart from rank-one SCFTs and Lagrangian gauge theories, which have been completely classified in [1]}, [2]}, [3]}, [4]}, [5]},
there exists a bewildering and constantly growing list of top-down constructions of 4d \({\cal N}=2\)  SCFTs that do not (yet?) admit a conventional Lagrangian description. Two broad classes involve compactifications of six-dimensional
SCFTs [6]}, [7]}, [8]}, [9]}, [10]}, [11]}, [12]}, [13]}, [14]} and geometric engineering on Calabi-Yau singularities in string theory [15]}, [16]}, [17]}, [18]}, [19]}, [20]}, [21]}.
